1. Field of the Invention
The present invention relates to a brewing apparatus, such as a coffeemaker, and more particularly to a hot water delivery control in a brewing apparatus.
2. Brief Description of Prior Developments
U.S. Patent Publication No. 2002/0051632 A1 discloses a first fixed power heater and two temperature sensors. The temperature sensors are used to control the power to the second heater. U.S. Pat. No. 5,738,001 discloses two temperature sensors located at an inlet and an outlet to the heat exchanger. U.S. Pat. No. 5,014,611 discloses a temperature sensor in a heat exchanger.
Coffeemakers are known which use single serve pouches or pods. There is a desire to provide good quality brewed liquid in a single serve brewing apparatus which can accommodate more than just a single mode of operation. This can add increased versatility to the brewing apparatus to accommodate different users or varying desires. For example, a user(s) might desire a single serve coffeemaker to make a small cup of coffee (such as seven ounces) or a larger cup of coffee (such as twelve ounces), or a small cup of relatively strong coffee (such as seven ounces, but stronger than an ordinary copy of coffee), or a cup of coffee with nondairy creamer automatically added. There is a desire to provide a single serve brewing apparatus which can accommodate these desires, but without expensive machinery associated with automatic mechanized coffee dispensers.
Consistently repeatable good quality brewed liquid requires accurate hot water quantity delivery and relatively precise hot water temperature. Conventional coffeemakers adjust the hot water heat to control water temperature. However, because of inherent lag times for hot water heater adjustments because of heat transfer rates from the heating element to the heat transfer member of the heater and then to the water, temperature control, especially in a single serve brewing apparatus dispensing a relatively small quantity of water such as only about seven to twelve ounces, is not good and does not produce consistently repeatable good quality brewed liquid. Thus, there is a need for a better control system for water temperature for a small serve brewing apparatus, such as an individual serving dispenser coffeemaker.